US President George W Bush said it was a "sad day" for the devastated communities
At least 23 people are dead after a series of tornadoes pummelled the US, leaving homes and business destroyed.
Fourteen people were killed in Missouri, seven in Oklahoma, and two in Georgia. US President George W Bush said it was a "sad day" for the devastated communities and promised federal aid.
"We send our prayers to those who lost their lives and the families of those who lost their lives, and the federal government will be moving hard to help," he said.
A spokeswoman for Missouri's emergency management department said search and rescue operations were continuing, and several people were in a critical condition in hospital.